Sb600 flash has a delay when i shoot on manual with my D90?

I like to shoot manual with my Nikon D90, but when i've got my sb600 flash connected, there's about a second delay maybe 2 seconds before it takes the picture with the flash, how do i change this? I remember when i first started using the flash, it never did this. It took the picture instantly, but then i messed with the controls and i must have changed the settings somewhere along the line. Can someone please help? I've tried reseting everything but i can't figure it out.

There are three possibilities that come to my mind:

- You may have the mirror lockup activated (option d10 in the menu). Then there should be a two second delay between pressing the shutter release button and taking the photo without the flash as well though.

- You are using the camera in self timer mode. That should be gone after turning it off and on again, so this is unlikely.

- You are doing an exposure based on the measured ambient light (of one or two seconds) and the flash is set to rear curtain sync. Then it will flash at the end of the exposure time, not at the start.

Jens is right.

The other possibility is that you are shooting in nearly complete darkness. Until your camera can focus, the shutter will not fire, thus NO flash either